function login() {
    var pass_word = document.getElementById("password").value;
    var user_name = document.getElementById("username").value;
    if (pass_word == "lidasong2014" && user_name == "lidasong") {
        window.open("index.html", "_self");
    } else
        alert("username:ldiasong\n\n password:lidasong2014");

}
